1. Field of the Invention
The instant invention relates generally to hydrofoil sailboats and more particularly to refinements in the control tiller for adjusting the hydrofoils which steer the frame and boat, and in the mechanism for altering the inclination of the sail.
2. Prior Art
The quest for a hydrofoil saiboat capable of attaining high speed even in low winds, wih a shallow draft, and reasonably high payloads has been long lived. One of the milestones in this arduous quest has been a book entitled "The 40-Knot Sailboat" written in 1963 by one of the present applicants and published by Grosset and Dunlop, New York, N.Y. To date, although several attempts have been made by the present applicants and numerous other skilled inventors to achieve all of these desirable operational characteristics, no single sailboat has been designed and/or built that has satisfied these criteria.
The evolutionary steps made toward realizing the abovenoted optimum operational characteristics are shown in U.S. Pat. No. 3,094,961, issued Jan. 25, 1963, U.S. Pat. No. 3,295,487, issued Jan. 3, 1967, U.S. Pat. No. 3,631,828, issed Jan. 4, 1972, U.S. Pat. No. 3,646,902, issued Mar. 7, 1972 and in U.S. Pat. No. 3,981,258, issued Sept. 21, 1976. All of these patents were awarded to Bernard Smith, one of the present applicants. The cited patents provide a discussion of the structure, dynamic forces and controls the one particular variety of hydrofoil sailing frames. Although each of the aerohydrofoils and hydrofoil sailboats disclosed possessed certain desirable features, all suffered from one or more deficiencies that limited their commercial acceptance.
For example, the hydrofoil sailboat disclosed in U.S. Pat. No. 3,981,258 employs a slender hull with one flat side facing the foil shaped sail and one convex side facing away from the sail. The sail is supported at its base ends by a pair of freely swiveling waterskis, and a ruddering hydrofoil is disposed at each end of the specially shaped hull. A crank is adjusted to take up, or release, the cables that position the ruddering hydrofoils, and the sail is inclined from the vertical to eliminate listing moments.
The hydrofoil sailboats patented by Smith prior to the sailboat shown in U.S. Pat. No. 3,981,258 suffered from one or more of the following defects: sorely limited load carrying capacity, unsatisfactory performance in low wind and inordinate draft, making such craft unsuitable for shallow water or beaching operations. Although the waterski sailboat disclosed in U.S. Pat. No. 3,981,258 solved most of the problems encountered with the hydrofoil sailboats disclosed in the eariler Smith patents, its control system (best shown in FIG. 4) proved too cumbersome in strong winds, requiring excessive manual force and dexterity. Moreover, the hydrofoils attached to the bow and stern of the hull of the waterski sailboat could not be conveniently inclined to supply additional lift at high speed.